Canning process



J. L. KIVLAN.

CANIMING PROCESS. APPLICAHQN FILED APR-28, I920.

Patented Aug. 3, 1920.

awvewtoz 85% y flu ow UNITED STATES PATENT OFFICE.

JOHN L. KIVLAN, 0F BOSTON, MASSACHUSETTS.

CANNING Application filed April 28,.

To all whom it may concern:

Be it known that I, JOHN L. KIVLAN, citizen of the United'States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Canning Processes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a process of canning, and more particularly to a process of hermetically sealing vessels generally.

One of the objects of the present invention is to substitute the normal pressure of the atmosphere, acting uniformly over the exterior of the jar closure against a substantial vacuum within the container, for an arbitrary mechanical pressure as heretofore used in the art.

Another object of the invention is to utilize preliminary means for applying and securing the jar closures prior to the production of the vacuum, and a still further object is to utilize means to prevent the failure of the proper degree of pressure due to possible variations of the temperature in the contents of the container with resultant variations in the vacuum.

One sheet of drawings accompanies this specification showing a desirable form of jar closure with which the present process can be properly applied, and in which:

Figure 1 is a vertical central section through the upper portion of a fragment of the jar with the closure applied and, clamped.

Fig. 2 is a side elevation of the closure of the upper portion of the jar with the clamping means disengaged to release the cover, shown partially in section. I

Fig. 3 is a front elevation of the top of a jar showing the mechanical fastener.

The particular form of fastener illustrated is shown and described more specifically in my pending application, Serial Number 281,307, and consists essentially of a jar having a ridge on its neck as indicated at C, two 2-link toggles D, L pivoted to an annular wire W, and having down turned nibs d. The jar cover T is provided with a circumferential groove determining a peripheral ridge, the nibs of the links being adapted to seat 1n said groove g. A. rubber gasket R is interposed between a suit- Specification of Letters Patent.

PROCESS.

Patented Aug. 3, 1920.

1920. Serial No. 377,20e.-

able shoulder on the neck of the jar and the cover as shown.

In the process which is the subject matter of the present invention the jar is filled with the product which is to be canned and the cover placed in position with the nibs of the clamping links placed in the groove 9 of the cover. The jar is then placed in water or some suitable heater and the temperature raised to the proper degree for sterilizing the contents. During this period, the cover being merely loosely held in position by the toggles and not clamp-ed, permits the escape of steam and other vapors from the jar. When the sterilization process has been continued for the proper length of time, the toggles are clamped.

With the form of clamping toggles illustrated, it is possible to determine accurately the degree of pressure which will be exerted by them upon the cover, and in this process this pressure is carefully determined by previous experiment and the proper mechanical construction of the toggles to create a pressure equal to or slightly less than that of the atmosphere, or 15 pounds to the square inch. Roughly speaking, it has been found that a force adapted to compress the gasket substantially one-thirty-second of an inch will be equivalent to that produced by the atmosphere. but it is obvious that this will be affected by the character of the rubber or other substance of which the gasket is constructed. The point of this inventionis that the toggles or other clamping means shall be ca able of exerting on the .cover a pressure sifbstantially equivalent to that of the atmosphere, and no more.

The top of the container being clamped by suitable mechanical means with a force equivalent to normal atmospheric pressure at the conclusion of the sterilization process, the jar is removed and allowed to cool, whereupon the shrinkage of the contents of the vessel will produce a substantial vacuum under the cover. As the vacuum within the container increases, the force exerted by the mechanical clamps will become increasingly potential rather than active, as the atmospheric pressure is substituted therefor. When the vessel is entirely cool, the closure will be held in sealing relation to the jar by atmospheric pressure alone operating uniformly over its entire surface. The utilization of normal atmospheric pressure, evenly distributed over the entire cover as a sealing means, operates in a great saving from breakage of glass tops, the avoidance of Wear and the possible cutting through of the gasket from an excessive or undue pressure and also a prolongation of the life of the metallic toggle elements which are normally relieved from strain.

By the form of construction shown, the clamping toggles having down-turned nibs engaged in a peripheral groove on the cover, this substitution of the atmospheric pressure for that previously exerted by the toggles will not operate to release or permit the falling off of the toggles, but the latter will be retained in an operative position so that should the temperature of the contents of the vessel be subsequently raised to reduce the negative vacuum pressure within the vessel, or the vacuum in any way dinnnished from any cause, the toggles will automatically function with a me-- chanical pressure equal to that of the atmos here operating on a vacuum.

hen 1t 1s desired to open a jar sealed by this process, it is only necessary to unclamp the inactive toggles and slightly heat the jar,'reducing the vacuum, when the top will be readily removable without undue force or tools.

The particular form of jar, closure and clamping toggles as shown are believed to be particularly adaptable to the application of the process specified, but other suitable means may obviously be adapted to applicants invention.

What I claim is:

In a canning process, the clamping of a cover on a heated filled jar with an external mechanical pressure equal to, but not exceeding, normal atmospheric pressure, allowing the jar to cool and the substitution of atmospheric pressure for said mechanical pressure as a sealing force, and the maintenance of said mechanical pressure potentially as a substitute for said atmospheric pressure.

In testimony whereof I aflix m si nature. JOHN L. I AN. 

